In UMTS (Universal Mobile Telecommunications System) networks, for the purpose of improving spectral efficiency and further improving data rates, by adopting HSDPA (High Speed Downlink Packet Access) and HSUPA (High Speed Uplink Packet Access), it is performed exploiting maximum features of the system based on W-CDMA (Wideband Code Division Multiple Access). For the UMTS network, for the purpose of further increasing high-speed data rates, providing low delay and the like, Long Term Evolution (LTE) has been studied.
In the 3G system, a fixed band of 5 MHz is substantially used, and it is possible to achieve transmission rates of approximately maximum 2 Mbps in downlink. Meanwhile, in the LTE system, using variable bands ranging from 1.4 MHz to 20 MHz, it is possible to achieve transmission rates of maximum 300 Mbps in downlink and about 75 Mbps in uplink. Further, in the UMTS network, for the purpose of further increasing the wide-band and high speed, successor systems to LTE have been discussed (for example, LTE Advanced (LTE-A)). For example, in LTE-A, it is scheduled to extend 20 MHz that is the maximum system band in LTE specifications to about 100 MHz.
Further, in the LTE-scheme system, the MIMO (Multi Input Multi Output) antenna system is proposed, as radio communication techniques for transmitting and receiving data with a plurality of antennas, and improving throughput and spectral efficiency (for example, see Non-patent Document 1). In the LTE-scheme system, the spatial multiplexing transmission mode (SU-MIMO (Single User MIMO)) is specified as a downlink MIMO mode. The spatial multiplexing transmission mode is a mode for spatially multiplexing signals of a plurality of streams in the same frequency and time to transmit, and is effective in improving throughput. In the LTE-scheme system, it is possible to transmit different transmission signals from maximum four transmission antennas in parallel to spatially multiplex. In LTE-A, it is scheduled to increase the maximum number (4) of transmission antennas in LTE specifications to “8”.
In the case of using such a spatial multiplexing transmission mode in an indoor environment, for example, it is conceivable that a plurality of transmission antennas is distributed and placed (Distributed placement) in a certain space. In the LTE-A-scheme system, maximum eight transmission antennas are distributed and placed, transmission signals of a plurality of streams are spatially multiplexed and transmitted from each of the transmission antennas, while the mobile station apparatus side properly divides such transmission signals of a plurality of streams to obtain a reception signal, and it is thereby possible to improve throughput.